1. A judgment or ruling made by a court, judge, or authority that is unfavorable to one party; a determination that goes against someone's interests
The court issued a decision against the defendant in the civil case.
O tribunal proferiu uma decisão contra o réu no processo civil.
2. A conclusion or determination made by a person or group that opposes or rejects a proposal, claim, or position
The committee made a decision against the merger proposal.
O comitê tomou uma decisão contra a proposta de fusão.